In the days of our grandfathers we had not only national independence but household independence. Every homestead had its own potash plant and soap factory. The frugal housewife dumped the maple wood ashes of the fireplace into a hollow log set up on end in the backyard. Water poured over the ashes leached out the lye, which drained into a bucket beneath. This gave her a solution of pearl ash or potassium carbonate whose concentration she tested with an egg as a hydrometer. In the meantime she had been saving up all the waste grease from the frying pan and pork rinds from the plate and by trying out these she got her soap fat. Then on a day set apart for this disagreeable process in chemical technology she boiled the fat and the lye together and got "soft soap," or as the chemist would call it, potassium stearate. If she wanted hard soap she "salted it out" with brine. The sodium stearate being less soluble was precipitated to the top and cooled into a solid cake that could be cut into bars by pack thread. But the frugal housewife threw away in the waste water what we now consider the most valuable ingredients, the potash and the glycerin.

But the old lye-leach is only to be found in ruins on an abandoned farm and we no longer burn wood at the rate of a log a night. In 1916 even under the stimulus of tenfold prices the amount of potash produced as pearl ash was only 412 tons—and we need 300,000 tons in some form. It would, of course, be very desirable as a conservation measure if all the sawdust and waste wood were utilized by charring it in retorts. The gas makes a handy fuel. The tar washed from the gas contains a lot of valuable products. And potash can be leached out of the charcoal or from its ashes whenever it is burned. But this at best would not go far toward solving the problem of our national supply.

There are other potash-bearing wastes that might be utilized. The cement mills which use feldspar in combination with limestone give off a potash dust, very much to the annoyance of their neighbors. This can be collected by running the furnace clouds into large settling chambers or long flues, where the dust may be caught in bags, or washed out by water sprays or thrown down by electricity. The blast furnaces for iron also throw off potash-bearing fumes.

Our six-million-ton crop of sugar beets contains some 12,000 tons of nitrogen, 4000 tons of phosphoric acid and 18,000 tons of potash, all of which is lost except where the waste liquors from the sugar factory are used in irrigating the beet land. The beet molasses, after extracting all the sugar possible by means of lime, leaves a waste liquor from which the potash can be recovered by evaporation and charring and leaching the residue. The Germans get 5000 tons of potassium cyanide and as much ammonium sulfate annually from the waste liquor of their beet sugar factories and if it pays them to save this it ought to pay us where potash is dearer. Various other industries can put in a bit when Uncle Sam passes around the contribution basket marked "Potash for the Poor." Wool wastes and fish refuse make valuable fertilizers, although they will not go far toward solving the problem. If we saved all our potash by-products they would not supply more than fifteen per cent. of our needs.

Though no potash beds comparable to those of Stassfurt have yet been discovered in the United States, yet in Nebraska, Utah, California and other western states there are a number of alkali lakes, wet or dry, containing a considerable amount of potash mixed with soda salts. Of these deposits the largest is Searles Lake, California. Here there are some twelve square miles of salt crust some seventy feet deep and the brine as pumped out contains about four per cent. of potassium chloride. The quantity is sufficient to supply the country for over twenty years, but it is not an easy or cheap job to separate the potassium from the sodium salts which are five times more abundant. These being less soluble than the potassium salts crystallize out first when the brine is evaporated. The final crystallization is done in vacuum pans as in getting sugar from the cane juice. In this way the American Trona Corporation is producing some 4500 tons of potash salts a month besides a thousand tons of borax. The borax which is contained in the brine to the extent of 1-1/2 per cent. is removed from the fertilizer for a double reason. It is salable by itself and it is detrimental to plant life.

Another mineral source of potash is alunite, which is a sort of natural alum, or double sulfate of potassium and aluminum, with about ten per cent. of potash. It contains a lot of extra alumina, but after roasting in a kiln the potassium sulfate can be leached out. The alunite beds near Marysville, Utah, were worked for all they were worth during the war, but the process does not give potash cheap enough for our needs in ordinary times.



The tourist going through Wyoming on the Union Pacific will have to the north of him what is marked on the map as the "Leucite Hills." If he looks up the word in the Unabridged that he carries in his satchel he will find that leucite is a kind of lava and that it contains potash. But he will also observe that the potash is combined with alumina and silica, which are hard to get out and useless when you get them out. One of the lavas of the Leucite Hills, that named from its native state "Wyomingite," gives fifty-seven per cent. of its potash in a soluble form on roasting with alunite—but this costs too much. The same may be said of all the potash feldspars and mica. They are abundant enough, but until we find a way of utilizing the by-products, say the silica in cement and the aluminum as a metal, they cannot solve our problem.

Since it is so hard to get potash from the land it has been suggested that we harvest the sea. The experts of the United States Department of Agriculture have placed high hopes in the kelp or giant seaweed which floats in great masses in the Pacific Ocean not far off from the California coast. This is harvested with ocean reapers run by gasoline engines and brought in barges to the shore, where it may be dried and used locally as a fertilizer or burned and the potassium chloride leached out of the charcoal ashes. But it is hard to handle the bulky, slimy seaweed cheaply enough to get out of it the small amount of potash it contains. So efforts are now being made to get more out of the kelp than the potash. Instead of burning the seaweed it is fermented in vats producing acetic acid (vinegar). From the resulting liquid can be obtained lime acetate, potassium chloride, potassium iodide, acetone, ethyl acetate (used as a solvent for guncotton) and algin, a gelatin-like gum.

PRODUCTION OF POTASH IN THE UNITED STATES

_____________ 1916 1917 Source Tons K_{2}O Per cent. Tons K_{2}O Per cent. of total of total production production ____ ___ __ ___ __ Mineral sources: Natural brines 3,994 41.1 20,652 63.4 Altmite 1,850 19.0 2,402 7.3 Dust from cement mills 1,621 5.0 Dust from blast furnaces 185 0.6 Organic Sources: Kelp 1,556 16.0 3,752 10.9 Molasses residue from distillers 1,845 19.0 2,846 8.8 Wood ashes 412 4.2 621 1.9 Waste liquors from beet-sugar refineries 369 1.1 Miscellaneous industrial wastes 63 .7 305 1.0 ___ __ ___ __ Total 9,720 100.0 32,573 100.0

—From U S. Bureau of Mines Report, 1918.

This table shows how inadequate was the reaction of the United States to the war demand for potassium salts. The minimum yearly requirements of the United States are estimated to be 250,000 tons of potash.

This completes our survey of the visible sources of potash in America. In 1917 under the pressure of the embargo and unprecedented prices the output of potash (K_{2}O) in various forms was raised to 32,573 tons, but this is only about a tenth as much as we needed. In 1918 potash production was further raised to 52,135 tons, chiefly through the increase of the output from natural brines to 39,255 tons, nearly twice what it was the year before. The rust in cotton and the resulting decrease in yield during the war are laid to lack of potash. Truck crops grown in soils deficient in potash do not stand transportation well. The Bureau of Animal Industry has shown in experiments in Aroostook County, Maine, that the addition of moderate amounts of potash doubled the yield of potatoes.

Professor Ostwald, the great Leipzig chemist, boasted in the war:

America went into the war like a man with a rope round his neck which is in his enemy's hands and is pretty tightly drawn. With its tremendous deposits Germany has a world monopoly in potash, a point of immense value which cannot be reckoned too highly when once this war is going to be settled. It is in Germany's power to dictate which of the nations shall have plenty of food and which shall starve.

If, indeed, some mineralogist or metallurgist will cut that rope by showing us a supply of cheap potash we will erect him a monument as big as Washington's. But Ostwald is wrong in supposing that America is as dependent as Germany upon potash. The bulk of our food crops are at present raised without the use of any fertilizers whatever.

As the cession of Lorraine in 1871 gave Germany the phosphates she needed for fertilizers so the retrocession of Alsace in 1919 gives France the potash she needed for fertilizers. Ten years before the war a bed of potash was discovered in the Forest of Monnebruck, near Hartmannsweilerkopf, the peak for which French and Germans contested so fiercely and so long. The layer of potassium salts is 16-1/2 feet thick and the total deposit is estimated to be 275,000,000 tons of potash. At any rate it is a formidable rival of Stassfurt and its acquisition by France breaks the German monopoly.

When we turn to the consideration of the third plant food we feel better. While the United States has no such monopoly of phosphates as Germany had of potash and Chile had of nitrates we have an abundance and to spare. Whereas we formerly imported about $17,000,000 worth of potash from Germany and $20,000,000 worth of nitrates from Chile a year we exported $7,000,000 worth of phosphates.

Whoever it was who first noticed that the grass grew thicker around a buried bone he lived so long ago that we cannot do honor to his powers of observation, but ever since then—whenever it was—old bones have been used as a fertilizer. But we long ago used up all the buffalo bones we could find on the prairies and our packing houses could not give us enough bone-meal to go around, so we have had to draw upon the old bone-yards of prehistoric animals. Deposits of lime phosphate of such origin were found in South Carolina in 1870 and in Florida in 1888. Since then the industry has developed with amazing rapidity until in 1913 the United States produced over three million tons of phosphates, nearly half of which was sent abroad. The chief source at present is the Florida pebbles, which are dredged up from the bottoms of lakes and rivers or washed out from the banks of streams by a hydraulic jet. The gravel is washed free from the sand and clay, screened and dried, and then is ready for shipment. The rock deposits of Florida and South Carolina are more limited than the pebble beds and may be exhausted in twenty-five or thirty years, but Tennessee and Kentucky have a lot in reserve and behind them are Idaho, Wyoming and other western states with millions of acres of phosphate land, so in this respect we are independent.

But even here the war hit us hard. For the calcium phosphate as it comes from the ground is not altogether available because it is not very soluble and the plants can only use what they can get in the water that they suck up from the soil. But if the phosphate is treated with sulfuric acid it becomes more soluble and this product is sold as "superphosphate." The sulfuric acid is made mostly from iron pyrite and this we have been content to import, over 800,000 tons of it a year, largely from Spain, although we have an abundance at home. Since the shortage of shipping shut off the foreign supply we are using more of our own pyrite and also our deposits of native sulfur along the Gulf coast. But as a consequence of this sulfuric acid during the war went up from $5 to $25 a ton and acidulated phosphates rose correspondingly.

Germany is short on natural phosphates as she is long on natural potash. But she has made up for it by utilizing a by-product of her steelworks. When phosphorus occurs in iron ore, even in minute amounts, it makes the steel brittle. Much of the iron ores of Alsace-Lorraine were formerly considered unworkable because of this impurity, but shortly after Germany took these provinces from France in 1871 a method was discovered by two British metallurgists, Thomas and Gilchrist, by which the phosphorus is removed from the iron in the process of converting it into steel. This consists in lining the crucible or converter with lime and magnesia, which takes up the phosphorus from the melted iron. This slag lining, now rich in phosphates, can be taken out and ground up for fertilizer. So the phosphorus which used to be a detriment is now an additional source of profit and this British invention has enabled Germany to make use of the territory she stole from France to outstrip England in the steel business. In 1910 Germany produced 2,000,000 tons of Thomas slag while only 160,000 tons were produced in the United Kingdom. The open hearth process now chiefly used in the United States gives an acid instead of a basic phosphate slag, not suitable as a fertilizer. The iron ore of America, with the exception of some of the southern ores, carries so small a percentage of phosphorus as to make a basic process inadvisable.

Recently the Germans have been experimenting with a combined fertilizer, Schroeder's potassium phosphate, which is said to be as good as Thomas slag for phosphates and as good as Stassfurt salts for potash. The American Cyanamid Company is just putting out a similar product, "Ammo-Phos," in which the ammonia can be varied from thirteen to twenty per cent. and the phosphoric acid from twenty to forty-seven per cent. so as to give the proportions desired for any crop. We have then the possibility of getting the three essential plant foods altogether in one compound with the elimination of most of the extraneous elements such as lime and magnesia, chlorids and sulfates.

For the last three hundred years the American people have been living on the unearned increment of the unoccupied land. But now that all our land has been staked out in homesteads and we cannot turn to new soil when we have used up the old, we must learn, as the older races have learned, how to keep up the supply of plant food. Only in this way can our population increase and prosper. As we have seen, the phosphate question need not bother us and we can see our way clear toward solving the nitrate question. We gave the Government $20,000,000 to experiment on the production of nitrates from the air and the results will serve for fields as well as firearms. But the question of an independent supply of cheap potash is still unsolved.



IV

COAL-TAR COLORS

If you put a bit of soft coal into a test tube (or, if you haven't a test tube, into a clay tobacco pipe and lute it over with clay) and heat it you will find a gas coming out of the end of the tube that will burn with a yellow smoky flame. After all the gas comes off you will find in the bottom of the test tube a chunk of dry, porous coke. These, then, are the two main products of the destructive distillation of coal. But if you are an unusually observant person, that is, if you are a born chemist with an eye to by-products, you will notice along in the middle of the tube where it is neither too hot nor too cold some dirty drops of water and some black sticky stuff. If you are just an ordinary person, you won't pay any attention to this because there is only a little of it and because what you are after is the coke and gas. You regard the nasty, smelly mess that comes in between as merely a nuisance because it clogs up and spoils your nice, clean tube.

Now that is the way the gas-makers and coke-makers—being for the most part ordinary persons and not born chemists—used to regard the water and tar that got into their pipes. They washed it out so as to have the gas clean and then ran it into the creek. But the neighbors—especially those who fished in the stream below the gas-works—made a fuss about spoiling the water, so the gas-men gave away the tar to the boys for use in celebrating the Fourth of July and election night or sold it for roofing.



But this same tar, which for a hundred years was thrown away and nearly half of which is thrown away yet in the United States, turns out to be one of the most useful things in the world. It is one of the strategic points in war and commerce. It wounds and heals. It supplies munitions and medicines. It is like the magic purse of Fortunatus from which anything wished for could be drawn. The chemist puts his hand into the black mass and draws out all the colors of the rainbow. This evil-smelling substance beats the rose in the production of perfume and surpasses the honey-comb in sweetness.

Bishop Berkeley, after having proved that all matter was in your mind, wrote a book to prove that wood tar would cure all diseases. Nobody reads it now. The name is enough to frighten them off: "Siris: A Chain of Philosophical Reflections and Inquiries Concerning the Virtues of Tar Water." He had a sort of mystical idea that tar contained the quintessence of the forest, the purified spirit of the trees, which could somehow revive the spirit of man. People said he was crazy on the subject, and doubtless he was, but the interesting thing about it is that not even his active and ingenious imagination could begin to suggest all of the strange things that can be got out of tar, whether wood or coal.

The reason why tar supplies all sorts of useful material is because it is indeed the quintessence of the forest, of the forests of untold millenniums if it is coal tar. If you are acquainted with a village tinker, one of those all-round mechanics who still survive in this age of specialization and can mend anything from a baby-carriage to an automobile, you will know that he has on the floor of his back shop a heap of broken machinery from which he can get almost anything he wants, a copper wire, a zinc plate, a brass screw or a steel rod. Now coal tar is the scrap-heap of the vegetable kingdom. It contains a little of almost everything that makes up trees. But you must not imagine that all that comes out of coal tar is contained in it. There are only about a dozen primary products extracted from coal tar, but from these the chemist is able to build up hundreds of thousands of new substances. This is true creative chemistry, for most of these compounds are not to be found in plants and never existed before they were made in the laboratory. It used to be thought that organic compounds, the products of vegetable and animal life, could only be produced by organized beings, that they were created out of inorganic matter by the magic touch of some "vital principle." But since the chemist has learned how, he finds it easier to make organic than inorganic substances and he is confident that he can reproduce any compound that he can analyze. He cannot only imitate the manufacturing processes of the plants and animals, but he can often beat them at their own game.

When coal is heated in the open air it is burned up and nothing but the ashes is left. But heat the coal in an enclosed vessel, say a big fireclay retort, and it cannot burn up because the oxygen of the air cannot get to it. So it breaks up. All parts of it that can be volatized at a high heat pass off through the outlet pipe and nothing is left in the retort but coke, that is carbon with the ash it contains. When the escaping vapors reach a cool part of the outlet pipe the oily and tarry matter condenses out. Then the gas is passed up through a tower down which water spray is falling and thus is washed free from ammonia and everything else that is soluble in water.

This process is called "destructive distillation." What products come off depends not only upon the composition of the particular variety of coal used, but upon the heat, pressure and rapidity of distillation. The way you run it depends upon what you are most anxious to have. If you want illuminating gas you will leave in it the benzene. If you are after the greatest yield of tar products, you impoverish the gas by taking out the benzene and get a blue instead of a bright yellow flame. If all you are after is cheap coke, you do not bother about the by-products, but let them escape and burn as they please. The tourist passing across the coal region at night could see through his car window the flames of hundreds of old-fashioned bee-hive coke-ovens and if he were of economical mind he might reflect that this display of fireworks was costing the country $75,000,000 a year besides consuming the irreplaceable fuel supply of the future. But since the gas was not needed outside of the cities and since the coal tar, if it could be sold at all, brought only a cent or two a gallon, how could the coke-makers be expected to throw out their old bee-hive ovens and put in the expensive retorts and towers necessary to the recovery of the by-products? But within the last ten years the by-product ovens have come into use and now nearly half our coke is made in them.

Although the products of destructive distillation vary within wide limits, yet the following table may serve to give an approximate idea of what may be got from a ton of soft coal:

1 ton of coal may give Gas, 12,000 cubic feet Liquor (Washings) ammonium sulfate (7-25 pounds) Tar (120 pounds) benzene (10-20 pounds) toluene (3 pounds) xylene (1-1/2 pounds) phenol (1/2 pound) naphthalene (3/8 pound) anthracene (1/4 pound) pitch (80 pounds) Coke (1200-1500 pounds)

When the tar is redistilled we get, among other things, the ten "crudes" which are fundamental material for making dyes. Their names are: benzene, toluene, xylene, phenol, cresol, naphthalene, anthracene, methyl anthracene, phenanthrene and carbazol.

There! I had to introduce you to the whole receiving line, but now that that ceremony is over we are at liberty to do as we do at a reception, meet our old friends, get acquainted with one or two more and turn our backs on the rest. Two of them, I am sure, you've met before, phenol, which is common carbolic acid, and naphthalene, which we use for mothballs. But notice one thing in passing, that not one of them is a dye. They are all colorless liquids or white solids. Also they all have an indescribable odor—all odors that you don't know are indescribable—which gives them and their progeny, even when odorless, the name of "aromatic compounds."



The most important of the ten because he is the father of the family is benzene, otherwise called benzol, but must not be confused with "benzine" spelled with an _i_ which we used to burn and clean our clothes with. "Benzine" is a kind of gasoline, but benzene _alias_ benzol has quite another constitution, although it looks and burns the same. Now the search for the constitution of benzene is one of the most exciting chapters in chemistry; also one of the most intricate chapters, but, in spite of that, I believe I can make the main point of it clear even to those who have never studied chemistry—provided they retain their childish liking for puzzles. It is really much like putting together the old six-block Chinese puzzle. The chemist can work better if he has a picture of what he is working with. Now his unit is the molecule, which is too small even to analyze with the microscope, no matter how high powered. So he makes up a sort of diagram of the molecule, and since he knows the number of atoms and that they are somehow attached to one another, he represents each atom by the first letter of its name and the points of attachment or bonds by straight lines connecting the atoms of the different elements. Now it is one of the rules of the game that all the bonds must be connected or hooked up with atoms at both ends, that there shall be no free hands reaching out into empty space. Carbon, for instance, has four bonds and hydrogen only one. They unite, therefore, in the proportion of one atom of carbon to four of hydrogen, or CH_{4}, which is methane or marsh gas and obviously the simplest of the hydrocarbons. But we have more complex hydrocarbons such as C_{6}H_{14}, known as hexane. Now if you try to draw the diagrams or structural formulas of these two compounds you will easily get

H H H H H H H H-C-H H-C-C-C-C-C-C-H H H H H H H H methane hexane

Each carbon atom, you see, has its four hands outstretched and duly grasped by one-handed hydrogen atoms or by neighboring carbon atoms in the chain. We can have such chains as long as you please, thirty or more in a chain; they are all contained in kerosene and paraffin.

So far the chemist found it east to construct diagrams that would satisfy his sense of the fitness of things, but when he found that benzene had the compostion C{6}H{6} he was puzzled. If you try to draw the picture of C{6}H{6} you will get something like this:

-C-C-C-C-C-C- H H H H H H

which is an absurdity because more than half of the carbon hands are waving wildly around asking to be held by something. Benzene, C{6}H{6}, evidently is like hexane, C{6}H{14}, in having a chain of six carbon atoms, but it has dropped its H's like an Englishman. Eight of the H's are missing.

Now one of the men who was worried over this benzene puzzle was the German chemist, Kekule. One evening after working over the problem all day he was sitting by the fire trying to rest, but he could not throw it off his mind. The carbon and the hydrogen atoms danced like imps on the carpet and as he watched them through his half-closed eyes he suddenly saw that the chain of six carbon atoms had joined at the ends and formed a ring while the six hydrogen atoms were holding on to the outside hands, in this fashion:

H C / H-C C-H H-C C-H // C H

Professor Kekule saw at once that the demons of his subconscious self had furnished him with a clue to the labyrinth, and so it proved. We need not suppose that the benzene molecule if we could see it would look anything like this diagram of it, but the theory works and that is all the scientist asks of any theory. By its use thousands of new compounds have been constructed which have proved of inestimable value to man. The modern chemist is not a discoverer, he is an inventor. He sits down at his desk and draws a "Kekule ring" or rather hexagon. Then he rubs out an H and hooks a nitro group (NO_{2}) on to the carbon in place of it; next he rubs out the O_{2} of the nitro group and puts in H_{2}; then he hitches on such other elements, or carbon chains and rings as he likes. He works like an architect designing a house and when he gets a picture of the proposed compounds to suit him he goes into the laboratory to make it. First he takes down the bottle of benzene and boils up some of this with nitric acid and sulfuric acid. This he puts in the nitro group and makes nitro-benzene, C_{6}H_{5}NO_{2}. He treats this with hydrogen, which displaces the oxygen and gives C_{6}H_{5}NH_{2} or aniline, which is the basis of so many of these compounds that they are all commonly called "the aniline dyes." But aniline itself is not a dye. It is a colorless or brownish oil.

It is not necessary to follow our chemist any farther now that we have seen how he works, but before we pass on we will just look at one of his products, not one of the most complicated but still complicated enough.



The name of this is sodium ditolyl-disazo-beta-naphthylamine- 6-sulfonic-beta-naphthylamine-3.6-disulfonate.

These chemical names of organic compounds are discouraging to the beginner and amusing to the layman, but that is because neither of them realizes that they are not really words but formulas. They are hyphenated because they come from Germany. The name given above is no more of a mouthful than "a-square-plus-two-a-b-plus-b-square" or "Third Assistant Secretary of War to the President of the United States of America." The trade name of this dye is Brilliant Congo, but while that is handier to say it does not mean anything. Nobody but an expert in dyes would know what it was, while from the formula name any chemist familiar with such compounds could draw its picture, tell how it would behave and what it was made from, or even make it. The old alchemist was a secretive and pretentious person and used to invent queer names for the purpose of mystifying and awing the ignorant. But the chemist in dropping the al- has dropped the idea of secrecy and his names, though equally appalling to the layman, are designed to reveal and not to conceal.

From this brief explanation the reader who has not studied chemistry will, I think, be able to get some idea of how these very intricate compounds are built up step by step. A completed house is hard to understand, but when we see the mason laying one brick on top of another it does not seem so difficult, although if we tried to do it we should not find it so easy as we think. Anyhow, let me give you a hint. If you want to make a good impression on a chemist don't tell him that he seems to you a sort of magician, master of a black art, and all that nonsense. The chemist has been trying for three hundred years to live down the reputation of being inspired of the devil and it makes him mad to have his past thrown up at him in this fashion. If his tactless admirers would stop saying "it is all a mystery and a miracle to me, and I cannot understand it" and pay attention to what he is telling them they would understand it and would find that it is no more of a mystery or a miracle than anything else. You can make an electrician mad in the same way by interrupting his explanation of a dynamo by asking: "But you cannot tell me what electricity really is." The electrician does not care a rap what electricity "really is"—if there really is any meaning to that phrase. All he wants to know is what he can do with it.



The tar obtained from the gas plant or the coke plant has now to be redistilled, giving off the ten "crudes" already mentioned and leaving in the still sixty-five per cent. of pitch, which may be used for roofing, paving and the like. The ten primary products or crudes are then converted into secondary products or "intermediates" by processes like that for the conversion of benzene into aniline. There are some three hundred of these intermediates in use and from them are built up more than three times as many dyes. The year before the war the American custom house listed 5674 distinct brands of synthetic dyes imported, chiefly from Germany, but some of these were trade names for the same product made by different firms or represented by different degrees of purity or form of preparation. Although the number of possible products is unlimited and over five thousand dyes are known, yet only about nine hundred are in use. We can summarize the situation so:

Coal-tar —> 10 crudes —> 300 intermediates —> 900 dyes —> 5000 brands.

Or, to borrow the neat simile used by Dr. Bernhard C. Hesse, it is like cloth-making where "ten fibers make 300 yarns which are woven into 900 patterns."

The advantage of the artificial dyestuffs over those found in nature lies in their variety and adaptability. Practically any desired tint or shade can be made for any particular fabric. If my lady wants a new kind of green for her stockings or her hair she can have it. Candies and jellies and drinks can be made more attractive and therefore more appetizing by varied colors. Easter eggs and Easter bonnets take on new and brighter hues.

More and more the chemist is becoming the architect of his own fortunes. He does not make discoveries by picking up a beaker and pouring into it a little from each bottle on the shelf to see what happens. He generally knows what he is after, and he generally gets it, although he is still often baffled and occasionally happens on something quite unexpected and perhaps more valuable than what he was looking for. Columbus was looking for India when he ran into an obstacle that proved to be America. William Henry Perkin was looking for quinine when he blundered into that rich and undiscovered country, the aniline dyes. William Henry was a queer boy. He had rather listen to a chemistry lecture than eat. When he was attending the City of London School at the age of thirteen there was an extra course of lectures on chemistry given at the noon recess, so he skipped his lunch to take them in. Hearing that a German chemist named Hofmann had opened a laboratory in the Royal College of London he headed for that. Hofmann obviously had no fear of forcing the young intellect prematurely. He perhaps had never heard that "the tender petals of the adolescent mind must be allowed to open slowly." He admitted young Perkin at the age of fifteen and started him on research at the end of his second year. An American student nowadays thinks he is lucky if he gets started on his research five years older than Perkin. Now if Hofmann had studied pedagogical psychology he would have been informed that nothing chills the ardor of the adolescent mind like being set at tasks too great for its powers. If he had heard this and believed it, he would not have allowed Perkin to spend two years in fruitless endeavors to isolate phenanthrene from coal tar and to prepare artificial quinine—and in that case Perkin would never have discovered the aniline dyes. But Perkin, so far from being discouraged, set up a private laboratory so he could work over-time. While working here during the Easter vacation of 1856—the date is as well worth remembering as 1066—he was oxidizing some aniline oil when he got what chemists most detest, a black, tarry mass instead of nice, clean crystals. When he went to wash this out with alcohol he was surprised to find that it gave a beautiful purple solution. This was "mauve," the first of the aniline dyes.

The funny thing about it was that when Perkin tried to repeat the experiment with purer aniline he could not get his color. It was because he was working with impure chemicals, with aniline containing a little toluidine, that he discovered mauve. It was, as I said, a lucky accident. But it was not accidental that the accident happened to the young fellow who spent his noonings and vacations at the study of chemistry. A man may not find what he is looking for, but he never finds anything unless he is looking for something.

Mauve was a product of creative chemistry, for it was a substance that had never existed before. Perkin's next great triumph, ten years later, was in rivaling Nature in the manufacture of one of her own choice products. This is alizarin, the coloring matter contained in the madder root. It was an ancient and oriental dyestuff, known as "Turkey red" or by its Arabic name of "alizari." When madder was introduced into France it became a profitable crop and at one time half a million tons a year were raised. A couple of French chemists, Robiquet and Colin, extracted from madder its active principle, alizarin, in 1828, but it was not until forty years later that it was discovered that alizarin had for its base one of the coal-tar products, anthracene. Then came a neck-and-neck race between Perkin and his German rivals to see which could discover a cheap process for making alizarin from anthracene. The German chemists beat him to the patent office by one day! Graebe and Liebermann filed their application for a patent on the sulfuric acid process as No. 1936 on June 25, 1869. Perkin filed his for the same process as No. 1948 on June 26. It had required twenty years to determine the constitution of alizarin, but within six months from its first synthesis the commercial process was developed and within a few years the sale of artificial alizarin reached $8,000,000 annually. The madder fields of France were put to other uses and even the French soldiers became dependent on made-in-Germany dyes for their red trousers. The British soldiers were placed in a similar situation as regards their red coats when after 1878 the azo scarlets put the cochineal bug out of business.

The modern chemist has robbed royalty of its most distinctive insignia, Tyrian purple. In ancient times to be "porphyrogene," that is "born to the purple," was like admission to the Almanach de Gotha at the present time, for only princes or their wealthy rivals could afford to pay $600 a pound for crimsoned linen. The precious dye is secreted by a snail-like shellfish of the eastern coast of the Mediterranean. From a tiny sac behind the head a drop of thick whitish liquid, smelling like garlic, can be extracted. If this is spread upon cloth of any kind and exposed to air and sunlight it turns first green, next blue and then purple. If the cloth is washed with soap—that is, set by alkali—it becomes a fast crimson, such as Catholic cardinals still wear as princes of the church. The Phoenician merchants made fortunes out of their monopoly, but after the fall of Tyre it became one of "the lost arts"—and accordingly considered by those whose faces are set toward the past as much more wonderful than any of the new arts. But in 1909 Friedlander put an end to the superstition by analyzing Tyrian purple and finding that it was already known. It was the same as a dye that had been prepared five years before by Sachs but had not come into commercial use because of its inferiority to others in the market. It required 12,000 of the mollusks to supply the little material needed for analysis, but once the chemist had identified it he did not need to bother the Murex further, for he could make it by the ton if he had wanted to. The coloring principle turned out to be a di-brom indigo, that is the same as the substance extracted from the Indian plant, but with the addition of two atoms of bromine. Why a particular kind of a shellfish should have got the habit of extracting this rare element from sea water and stowing it away in this peculiar form is "one of those things no fellow can find out." But according to the chemist the Murex mollusk made a mistake in hitching the bromine to the wrong carbon atoms. He finds as he would word it that the 6:6' di-brom indigo secreted by the shellfish is not so good as the 5:5' di-brom indigo now manufactured at a cheap rate and in unlimited quantity. But we must not expect too much of a mollusk's mind. In their cheapness lies the offense of the aniline dyes in the minds of some people. Our modern aristocrats would delight to be entitled "porphyrogeniti" and to wear exclusive gowns of "purple and scarlet from the isles of Elishah" as was done in Ezekiel's time, but when any shopgirl or sailor can wear the royal color it spoils its beauty in their eyes. Applied science accomplishes a real democracy such as legislation has ever failed to establish.

Any kind of dye found in nature can be made in the laboratory whenever its composition is understood and usually it can be made cheaper and purer than it can be extracted from the plant. But to work out a profitable process for making it synthetically is sometimes a task requiring high skill, persistent labor and heavy expenditure. One of the latest and most striking of these achievements of synthetic chemistry is the manufacture of indigo.

Indigo is one of the oldest and fastest of the dyestuffs. To see that it is both ancient and lasting look at the unfaded blue cloths that enwrap an Egyptian mummy. When Caesar conquered our British ancestors he found them tattooed with woad, the native indigo. But the chief source of indigo was, as its name implies, India. In 1897 nearly a million acres in India were growing the indigo plant and the annual value of the crop was $20,000,000. Then the fall began and by 1914 India was producing only $300,000 worth! What had happened to destroy this profitable industry? Some blight or insect? No, it was simply that the Badische Anilin-und-Soda Fabrik had worked out a practical process for making artificial indigo.

That indigo on breaking up gave off aniline was discovered as early as 1840. In fact that was how aniline got its name, for when Fritzsche distilled indigo with caustic soda he called the colorless distillate "aniline," from the Arabic name for indigo, "anil" or "al-nil," that is, "the blue-stuff." But how to reverse the process and get indigo from aniline puzzled chemists for more than forty years until finally it was solved by Adolf von Baeyer of Munich, who died in 1917 at the age of eighty-four. He worked on the problem of the constitution of indigo for fifteen years and discovered several ways of making it. It is possible to start from benzene, toluene or naphthalene. The first process was the easiest, but if you will refer to the products of the distillation of tar you will find that the amount of toluene produced is less than the naphthalene, which is hard to dispose of. That is, if a dye factory had worked out a process for making indigo from toluene it would not be practicable because there was not enough toluene produced to supply the demand for indigo. So the more complicated napthalene process was chosen in preference to the others in order to utilize this by-product.

The Badische Anilin-und-Soda Fabrik spent $5,000,000 and seventeen years in chemical research before they could make indigo, but they gained a monopoly (or, to be exact, ninety-six per cent.) of the world's production. A hundred years ago indigo cost as much as $4 a pound. In 1914 we were paying fifteen cents a pound for it. Even the pauper labor of India could not compete with the German chemists at that price. At the beginning of the present century Germany was paying more than $3,000,000 a year for indigo. Fourteen years later Germany was selling indigo to the amount of $12,600,000. Besides its cheapness, artificial indigo is preferable because it is of uniform quality and greater purity. Vegetable indigo contains from forty to eighty per cent. of impurities, among them various other tinctorial substances. Artificial indigo is made pure and of any desired strength, so the dyers can depend on it.

The value of the aniline colors lies in their infinite variety. Some are fast, some will fade, some will stand wear and weather as long as the fabric, some will wash out on the spot. Dyes can be made that will attach themselves to wool, to silk or to cotton, and give it any shade of any color. The period of discovery by accident has long gone by. The chemist nowadays decides first just what kind of a dye he wants, and then goes to work systematically to make it. He begins by drawing a diagram of the molecule, double-linking nitrogen or carbon and oxygen atoms to give the required intensity, putting in acid or basic radicals to fasten it to the fiber, shifting the color back and forth along the spectrum at will by introducing methyl groups, until he gets it just to his liking.

Art can go ahead of nature in the dyestuff business. Before man found that he could make all the dyes he wanted from the tar he had been burning up at home he searched the wide world over to find colors by which he could make himself—or his wife—garments as beautiful as those that arrayed the flower, the bird and the butterfly. He sent divers down into the Mediterranean to rob the murex of his purple. He sent ships to the new world to get Brazil wood and to the oldest world for indigo. He robbed the lady cochineal of her scarlet coat. Why these peculiar substances were formed only by these particular plants, mussels and insects it is hard to understand. I don't know that Mrs. Cacti Coccus derived any benefit from her scarlet uniform when khaki would be safer, and I can't imagine that to a shellfish it was of advantage to turn red as it rots or to an indigo plant that its leaves in decomposing should turn blue. But anyhow, it was man that took advantage of them until he learned how to make his own dyestuffs.

Our independent ancestors got along so far as possible with what grew in the neighborhood. Sweetapple bark gave a fine saffron yellow. Ribbons were given the hue of the rose by poke berry juice. The Confederates in their butternut-colored uniform were almost as invisible as if in khaki or feldgrau. Madder was cultivated in the kitchen garden. Only logwood from Jamaica and indigo from India had to be imported. That we are not so independent today is our own fault, for we waste enough coal tar to supply ourselves and other countries with all the new dyes needed. It is essentially a question of economy and organization. We have forgotten how to economize, but we have learned how to organize.

The British Government gave the discoverer of mauve a title, but it did not give him any support in his endeavors to develop the industry, although England led the world in textiles and needed more dyes than any other country. So in 1874 Sir William Perkin relinquished the attempt to manufacture the dyes he had discovered because, as he said, Oxford and Cambridge refused to educate chemists or to carry on research. Their students, trained in the classics for the profession of being a gentleman, showed a decided repugnance to the laboratory on account of its bad smells. So when Hofmann went home he virtually took the infant industry along with him to Germany, where Ph.D.'s were cheap and plentiful and not afraid of bad smells. There the business throve amazingly, and by 1914 the Germans were manufacturing more than three-fourths of all the coal-tar products of the world and supplying material for most of the rest. The British cursed the universities for thus imperiling the nation through their narrowness and neglect; but this accusation, though natural, was not altogether fair, for at least half the blame should go to the British dyer, who did not care where his colors came from, so long as they were cheap. When finally the universities did turn over a new leaf and began to educate chemists, the manufacturers would not employ them. Before the war six English factories producing dyestuffs employed only 35 chemists altogether, while one German color works, the Hoechster Farbwerke, employed 307 expert chemists and 74 technologists.

This firm united with the six other leading dye companies of Germany on January 1, 1916, to form a trust to last for fifty years. During this time they will maintain uniform prices and uniform wage scales and hours of labor, and exchange patents and secrets. They will divide the foreign business pro rata and share the profits. The German chemical works made big profits during the war, mostly from munitions and medicines, and will be, through this new combination, in a stronger position than ever to push the export trade.

As a consequence of letting the dye business get away from her, England found herself in a fix when war broke out. She did not have dyes for her uniforms and flags, and she did not have drugs for her wounded. She could not take advantage of the blockade to capture the German trade in Asia and South America, because she could not color her textiles. A blue cotton dyestuff that sold before the war at sixty cents a pound, brought $34 a pound. A bright pink rhodamine formerly quoted at a dollar a pound jumped to $48. When one keg of dye ordinarily worth $15 was put up at forced auction sale in 1915 it was knocked down at $1500. The Highlanders could not get the colors for their kilts until some German dyes were smuggled into England. The textile industries of Great Britain, that brought in a billion dollars a year and employed one and a half million workers, were crippled for lack of dyes. The demand for high explosives from the front could not be met because these also are largely coal-tar products. Picric acid is both a dye and an explosive. It is made from carbolic acid and the famous trinitrotoluene is made from toluene, both of which you will find in the list of the ten fundamental "crudes."

Both Great Britain and the United States realized the danger of allowing Germany to recover her former monopoly, and both have shown a readiness to cast overboard their traditional policies to meet this emergency. The British Government has discovered that a country without a tariff is a land without walls. The American Government has discovered that an industry is not benefited by being cut up into small pieces. Both governments are now doing all they can to build up big concerns and to provide them with protection. The British Government assisted in the formation of a national company for the manufacture of synthetic dyes by taking one-sixth of the stock and providing $500,000 for a research laboratory. But this effort is now reported to be "a great failure" because the Government put it in charge of the politicians instead of the chemists.

The United States, like England, had become dependent upon Germany for its dyestuffs. We imported nine-tenths of what we used and most of those that were produced here were made from imported intermediates. When the war broke out there were only seven firms and 528 persons employed in the manufacture of dyes in the United States. One of these, the Schoelkopf Aniline and Chemical Works, of Buffalo, deserves mention, for it had stuck it out ever since 1879, and in 1914 was making 106 dyes. In June, 1917, this firm, with the encouragement of the Government Bureau of Foreign and Domestic Commerce, joined with some of the other American producers to form a trade combination, the National Aniline and Chemical Company. The Du Pont Company also entered the field on an extensive scale and soon there were 118 concerns engaged in it with great profit. During the war $200,000,000 was invested in the domestic dyestuff industry. To protect this industry Congress put on a specific duty of five cents a pound and an ad valorem duty of 30 per cent. on imported dyestuffs; but if, after five years, American manufacturers are not producing 60 per cent. in value of the domestic consumption, the protection is to be removed. For some reason, not clearly understood and therefore hotly discussed, Congress at the last moment struck off the specific duty from two of the most important of the dyestuffs, indigo and alizarin, as well as from all medicinals and flavors.

The manufacture of dyes is not a big business, but it is a strategic business. Heligoland is not a big island, but England would have been glad to buy it back during the war at a high price per square yard. American industries employing over two million men and women and producing over three billion dollars' worth of products a year are dependent upon dyes. Chief of these is of course textiles, using more than half the dyes; next come leather, paper, paint and ink. We have been importing more than $12,000,000 worth of coal-tar products a year, but the cottonseed oil we exported in 1912 would alone suffice to pay that bill twice over. But although the manufacture of dyes cannot be called a big business, in comparison with some others, it is a paying business when well managed. The German concerns paid on an average 22 per cent. dividends on their capital and sometimes as high as 50 per cent. Most of the standard dyes have been so long in use that the patents are off and the processes are well enough known. We have the coal tar and we have the chemists, so there seems no good reason why we should not make our own dyes, at least enough of them so we will not be caught napping as we were in 1914. It was decidedly humiliating for our Government to have to beg Germany to sell us enough colors to print our stamps and greenbacks and then have to beg Great Britain for permission to bring them over by Dutch ships.

The raw material for the production of coal-tar products we have in abundance if we will only take the trouble to save it. In 1914 the crude light oil collected from the coke-ovens would have produced only about 4,500,000 gallons of benzol and 1,500,000 gallons of toluol, but in 1917 this output was raised to 40,200,000 gallons of benzol and 10,200,000 of toluol. The toluol was used mostly in the manufacture of trinitrotoluol for use in Europe. When the war broke out in 1914 it shut off our supply of phenol (carbolic acid) for which we were dependent upon foreign sources. This threatened not only to afflict us with headaches by depriving us of aspirin but also to removed the consolation of music, for phenol is used in making phonographic records. Mr. Edison with his accustomed energy put up a factory within a few weeks for the manufacture of synthetic phenol. When we entered the war the need for phenol became yet more imperative, for it was needed to make picric acid for filling bombs. This demand was met, and in 1917 there were fifteen new plants turning out 64,146,499 pounds of phenol valued at $23,719,805.

Some of the coal-tar products, as we see, serve many purposes. For instance, picric acid appears in three places in this book. It is a high explosive. It is a powerful and permanent yellow dye as any one who has touched it knows. Thirdly it is used as an antiseptic to cover burned skin. Other coal-tar dyes are used for the same purpose, "malachite green," "brilliant green," "crystal violet," "ethyl violet" and "Victoria blue," so a patient in a military hospital is decorated like an Easter egg. During the last five years surgeons have unfortunately had unprecedented opportunities for the study of wounds and fortunately they have been unprecedentedly successful in finding improved methods of treating them. In former wars a serious wound meant usually death or amputation. Now nearly ninety per cent. of the wounded are able to continue in the service. The reason for this improvement is that medicines are now being made to order instead of being gathered "from China to Peru." The old herb doctor picked up any strange plant that he could find and tried it on any sick man that would let him. This empirical method, though hard on the patients, resulted in the course of five thousand years in the discovery of a number of useful remedies. But the modern medicine man when he knows the cause of the disease is usually able to devise ways of counteracting it directly. For instance, he knows, thanks to Pasteur and Metchnikoff, that the cause of wound infection is the bacterial enemies of man which swarm by the million into any breach in his protective armor, the skin. Now when a breach is made in a line of intrenchments the defenders rush troops to the threatened spot for two purposes, constructive and destructive, engineers and warriors, the former to build up the rampart with sandbags, the latter to kill the enemy. So when the human body is invaded the blood brings to the breach two kinds of defenders. One is the serum which neutralizes the bacterial poison and by coagulating forms a new skin or scab over the exposed flesh. The other is the phagocytes or white corpuscles, the free lances of our corporeal militia, which attack and kill the invading bacteria. The aim of the physician then is to aid these defenders as much as possible without interfering with them. Therefore the antiseptic he is seeking is one that will assist the serum in protecting and repairing the broken tissues and will kill the hostile bacteria without killing the friendly phagocytes. Carbolic acid, the most familiar of the coal-tar antiseptics, will destroy the bacteria when it is diluted with 250 parts of water, but unfortunately it puts a stop to the fighting activities of the phagocytes when it is only half that strength, or one to 500, so it cannot destroy the infection without hindering the healing.

In this search for substances that would attack a specific disease germ one of the leading investigators was Prof. Paul Ehrlich, a German physician of the Hebrew race. He found that the aniline dyes were useful for staining slides under the microscope, for they would pick out particular cells and leave others uncolored and from this starting point he worked out organic and metallic compounds which would destroy the bacteria and parasites that cause some of the most dreadful of diseases. A year after the war broke out Professor Ehrlich died while working in his laboratory on how to heal with coal-tar compounds the wounds inflicted by explosives from the same source.

One of the most valuable of the aniline antiseptics employed by Ehrlich is flavine or, if the reader prefers to call it by its full name, diaminomethylacridinium chloride. Flavine, as its name implies, is a yellow dye and will kill the germs causing ordinary abscesses when in solution as dilute as one part of the dye to 200,000 parts of water, but it does not interfere with the bactericidal action of the white blood corpuscles unless the solution is 400 times as strong as this, that is one part in 500. Unlike carbolic acid and other antiseptics it is said to stimulate the serum instead of impairing its activity. Another antiseptic of the coal-tar family which has recently been brought into use by Dr. Dakin of the Rockefeller Institute is that called by European physicians chloramine-T and by American physicians chlorazene and by chemists para-toluene-sodium-sulfo-chloramide.

This may serve to illustrate how a chemist is able to make such remedies as the doctor needs, instead of depending upon the accidental by-products of plants. On an earlier page I explained how by starting with the simplest of ring-compounds, the benzene of coal tar, we could get aniline. Suppose we go a step further and boil the aniline oil with acetic acid, which is the acid of vinegar minus its water. This easy process gives us acetanilid, which when introduced into the market some years ago under the name of "antifebrin" made a fortune for its makers.

The making of medicines from coal tar began in 1874 when Kolbe made salicylic acid from carbolic acid. Salicylic acid is a rheumatism remedy and had previously been extracted from willow bark. If now we treat salicylic acid with concentrated acetic acid we get "aspirin." From aniline again are made "phenacetin," "antipyrin" and a lot of other drugs that have become altogether too popular as headache remedies—say rather "headache relievers."

Another class of synthetics equally useful and likewise abused, are the soporifics, such as "sulphonal," "veronal" and "medinal." When it is not desired to put the patient to sleep but merely to render insensible a particular place, as when a tooth is to be pulled, cocain may be used. This, like alcohol and morphine, has proved a curse as well as a blessing and its sale has had to be restricted because of the many victims to the habit of using this drug. Cocain is obtained from the leaves of the South American coca tree, but can be made artificially from coal-tar products. The laboratory is superior to the forest because other forms of local anesthetics, such as eucain and novocain, can be made that are better than the natural alkaloid because more effective and less poisonous.

I must not forget to mention another lot of coal-tar derivatives in which some of my readers will take a personal interest. That is the photographic developers. I am old enough to remember when we used to develop our plates in ferrous sulfate solution and you never saw nicer negatives than we got with it. But when pyrogallic acid came in we switched over to that even though it did stain our fingers and sometimes our plates. Later came a swarm of new organic reducing agents under various fancy names, such as metol, hydro (short for hydro-quinone) and eikongen ("the image-maker"). Every fellow fixed up his own formula and called his fellow-members of the camera club fools for not adopting it though he secretly hoped they would not.

Under the double stimulus of patriotism and high prices the American drug and dyestuff industry developed rapidly. In 1917 about as many pounds of dyes were manufactured in America as were imported in 1913 and our exports of American-made dyes exceeded in value our imports before the war. In 1914 the output of American dyes was valued at $2,500,000. In 1917 it amounted to over $57,000,000. This does not mean that the problem was solved, for the home products were not equal in variety and sometimes not in quality to those made in Germany. Many valuable dyes were lacking and the cost was of course much higher. Whether the American industry can compete with the foreign in an open market and on equal terms is impossible to say because such conditions did not prevail before the war and they are not going to prevail in the future. Formerly the large German cartels through their agents and branches in this country kept the business in their own hands and now the American manufacturers are determined to maintain the independence they have acquired. They will not depend hereafter upon the tariff to cut off competition but have adopted more effective measures. The 4500 German chemical patents that had been seized by the Alien Property Custodian were sold by him for $250,000 to the Chemical Foundation, an association of American manufacturers organized "for the Americanization of such institutions as may be affected thereby, for the exclusion or elimination of alien interests hostile or detrimental to said industries and for the advancement of chemical and allied science and industry in the United States." The Foundation has a large fighting fund so that it "may be able to commence immediately and prosecute with the utmost vigor infringement proceedings whenever the first German attempt shall hereafter be made to import into this country."

So much mystery has been made of the achievements of German chemists—as though the Teutonic brain had a special lobe for that faculty, lacking in other craniums—that I want to quote what Dr. Hesse says about his first impressions of a German laboratory of industrial research:

Directly after graduating from the University of Chicago in 1896, I entered the employ of the largest coal-tar dye works in the world at its plant in Germany and indeed in one of its research laboratories. This was my first trip outside the United States and it was, of course, an event of the first magnitude for me to be in Europe, and, as a chemist, to be in Germany, in a German coal-tar dye plant, and to cap it all in its research laboratory—a real sanctum sanctorum for chemists. In a short time the daily routine wore the novelty off my experience and I then settled down to calm analysis and dispassionate appraisal of my surroundings and to compare what was actually before and around me with my expectations. I found that the general laboratory equipment was no better than what I had been accustomed to; that my colleagues had no better fundamental training than I had enjoyed nor any better fact—or manipulative—equipment than I; that those in charge of the work had no better general intellectual equipment nor any more native ability than had my instructors; in short, there was nothing new about it all, nothing that we did not have back home, nothing—except the specific problems that were engaging their attention, and the special opportunities of attacking them. Those problems were of no higher order of complexity than those I had been accustomed to for years, in fact, most of them were not very complex from a purely intellectual viewpoint. There was nothing inherently uncanny, magical or wizardly about their occupation whatever. It was nothing but plain hard work and keeping everlastingly at it. Now, what was the actual thing behind that chemical laboratory that we did not have at home? It was money, willing to back such activity, convinced that in the final outcome, a profit would be made; money, willing to take university graduates expecting from them no special knowledge other than a good and thorough grounding in scientific research and provide them with opportunity to become specialists suited to the factory's needs.

It is evidently not impossible to make the United States self-sufficient in the matter of coal-tar products. We've got the tar; we've got the men; we've got the money, too. Whether such a policy would pay us in the long run or whether it is necessary as a measure of military or commercial self-defense is another question that cannot here be decided. But whatever share we may have in it the coal-tar industry has increased the economy of civilization and added to the wealth of the world by showing how a waste by-product could be utilized for making new dyes and valuable medicines, a better use for tar than as fuel for political bonfires and as clothing for the nakedness of social outcasts.



V

SYNTHETIC PERFUMES AND FLAVORS

The primitive man got his living out of such wild plants and animals as he could find. Next he, or more likely his wife, began to cultivate the plants and tame the animals so as to insure a constant supply. This was the first step toward civilization, for when men had to settle down in a community (civitas) they had to ameliorate their manners and make laws protecting land and property. In this settled and orderly life the plants and animals improved as well as man and returned a hundredfold for the pains that their master had taken in their training. But still man was dependent upon the chance bounties of nature. He could select, but he could not invent. He could cultivate, but he could not create. If he wanted sugar he had to send to the West Indies. If he wanted spices he had to send to the East Indies. If he wanted indigo he had to send to India. If he wanted a febrifuge he had to send to Peru. If he wanted a fertilizer he had to send to Chile. If he wanted rubber he had to send to the Congo. If he wanted rubies he had to send to Mandalay. If he wanted otto of roses he had to send to Turkey. Man was not yet master of his environment.

This period of cultivation, the second stage of civilization, began before the dawn of history and lasted until recent times. We might almost say up to the twentieth century, for it was not until the fundamental laws of heredity were discovered that man could originate new species of plants and animals according to a predetermined plan by combining such characteristics as he desired to perpetuate. And it was not until the fundamental laws of chemistry were discovered that man could originate new compounds more suitable to his purpose than any to be found in nature. Since the progress of mankind is continuous it is impossible to draw a date line, unless a very jagged one, along the frontier of human culture, but it is evident that we are just entering upon the third era of evolution in which man will make what he needs instead of trying to find it somewhere. The new epoch has hardly dawned, yet already a man may stay at home in New York or London and make his own rubber and rubies, his own indigo and otto of roses. More than this, he can make gems and colors and perfumes that never existed since time began. The man of science has signed a declaration of independence of the lower world and we are now in the midst of the revolution.

Our eyes are dazzled by the dawn of the new era. We know what the hunter and the horticulturist have already done for man, but we cannot imagine what the chemist can do. If we look ahead through the eyes of one of the greatest of French chemists, Berthelot, this is what we shall see:

The problem of food is a chemical problem. Whenever energy can be obtained economically we can begin to make all kinds of aliment, with carbon borrowed from carbonic acid, hydrogen taken from the water and oxygen and nitrogen drawn from the air.... The day will come when each person will carry for his nourishment his little nitrogenous tablet, his pat of fatty matter, his package of starch or sugar, his vial of aromatic spices suited to his personal taste; all manufactured economically and in unlimited quantities; all independent of irregular seasons, drought and rain, of the heat that withers the plant and of the frost that blights the fruit; all free from pathogenic microbes, the origin of epidemics and the enemies of human life. On that day chemistry will have accomplished a world-wide revolution that cannot be estimated. There will no longer be hills covered with vineyards and fields filled with cattle. Man will gain in gentleness and morality because he will cease to live by the carnage and destruction of living creatures.... The earth will be covered with grass, flowers and woods and in it the human race will dwell in the abundance and joy of the legendary age of gold—provided that a spiritual chemistry has been discovered that changes the nature of man as profoundly as our chemistry transforms material nature.

But this is looking so far into the future that we can trust no man's eyesight, not even Berthelot's. There is apparently no impossibility about the manufacture of synthetic food, but at present there is no apparent probability of it. There is no likelihood that the laboratory will ever rival the wheat field. The cornstalk will always be able to work cheaper than the chemist in the manufacture of starch. But in rarer and choicer products of nature the chemist has proved his ability to compete and even to excel.

What have been from the dawn of history to the rise of synthetic chemistry the most costly products of nature? What could tempt a merchant to brave the perils of a caravan journey over the deserts of Asia beset with Arab robbers? What induced the Portuguese and Spanish mariners to risk their frail barks on perilous waters of the Cape of Good Hope or the Horn? The chief prizes were perfumes, spices, drugs and gems. And why these rather than what now constitutes the bulk of oversea and overland commerce? Because they were precious, portable and imperishable. If the merchant got back safe after a year or two with a little flask of otto of roses, a package of camphor and a few pearls concealed in his garments his fortune was made. If a single ship of the argosy sent out from Lisbon came back with a load of sandalwood, indigo or nutmeg it was regarded as a successful venture. You know from reading the Bible, or if not that, from your reading of Arabian Nights, that a few grains of frankincense or a few drops of perfumed oil were regarded as gifts worthy the acceptance of a king or a god. These products of the Orient were equally in demand by the toilet and the temple. The unctorium was an adjunct of the Roman bathroom. Kings had to be greased and fumigated before they were thought fit to sit upon a throne. There was a theory, not yet altogether extinct, that medicines brought from a distance were most efficacious, especially if, besides being expensive, they tasted bad like myrrh or smelled bad like asafetida. And if these failed to save the princely patient he was embalmed in aromatics or, as we now call them, antiseptics of the benzene series.

Today, as always, men are willing to pay high for the titillation of the senses of smell and taste. The African savage will trade off an ivory tusk for a piece of soap reeking with synthetic musk. The clubman will pay $10 for a bottle of wine which consists mostly of water with about ten per cent. of alcohol, worth a cent or two, but contains an unweighable amount of the "bouquet" that can only be produced on the sunny slopes of Champagne or in the valley of the Rhine. But very likely the reader is quite as extravagant, for when one buys the natural violet perfumery he is paying at the rate of more than $10,000 a pound for the odoriferous oil it contains; the rest is mere water and alcohol. But you would not want the pure undiluted oil if you could get it, for it is unendurable. A single whiff of it paralyzes your sense of smell for a time just as a loud noise deafens you.

Of the five senses, three are physical and two chemical. By touch we discern pressures and surface textures. By hearing we receive impressions of certain air waves and by sight of certain ether waves. But smell and taste lead us to the heart of the molecule and enable us to tell how the atoms are put together. These twin senses stand like sentries at the portals of the body, where they closely scrutinize everything that enters. Sounds and sights may be disagreeable, but they are never fatal. A man can live in a boiler factory or in a cubist art gallery, but he cannot live in a room containing hydrogen sulfide. Since it is more important to be warned of danger than guided to delights our senses are made more sensitive to pain than pleasure. We can detect by the smell one two-millionth of a milligram of oil of roses or musk, but we can detect one two-billionth of a milligram of mercaptan, which is the vilest smelling compound that man has so far invented. If you do not know how much a milligram is consider a drop picked up by the point of a needle and imagine that divided into two billion parts. Also try to estimate the weight of the odorous particles that guide a dog to the fox or warn a deer of the presence of man. The unaided nostril can rival the spectroscope in the detection and analysis of unweighable amounts of matter.

What we call flavor or savor is a joint effect of taste and odor in which the latter predominates. There are only four tastes of importance, acid, alkaline, bitter and sweet. The acid, or sour taste, is the perception of hydrogen atoms charged with positive electricity. The alkaline, or soapy taste, is the perception of hydroxyl radicles charged with negative electricity. The bitter and sweet tastes and all the odors depend upon the chemical constitution of the compound, but the laws of the relation have not yet been worked out. Since these sense organs, the taste and smell buds, are sunk in the moist mucous membrane they can only be touched by substances soluble in water, and to reach the sense of smell they must also be volatile so as to be diffused in the air inhaled by the nose. The "taste" of food is mostly due to the volatile odors of it that creep up the back-stairs into the olfactory chamber.

A chemist given an unknown substance would have to make an elementary analysis and some tedious tests to determine whether it contained methyl or ethyl groups, whether it was an aldehyde or an ester, whether the carbon atoms were singly or doubly linked and whether it was an open chain or closed. But let him get a whiff of it and he can give instantly a pretty shrewd guess as to these points. His nose knows.

Although the chemist does not yet know enough to tell for certain from looking at the structural formula what sort of odor the compound would have or whether it would have any, yet we can divide odoriferous substances into classes according to their constitution. What are commonly known as "fruity" odors belong mostly to what the chemist calls the fatty or aliphatic series. For instance, we may have in a ripe fruit an alcohol (say ethyl or common alcohol) and an acid (say acetic or vinegar) and a combination of these, the ester or organic salt (in this case ethyl acetate), which is more odorous than either of its components. These esters of the fatty acids give the characteristic savor to many of our favorite fruits, candies and beverages. The pear flavor, amyl acetate, is made from acetic acid and amyl alcohol—though amyl alcohol (fusel oil) has a detestable smell. Pineapple is ethyl butyrate—but the acid part of it (butyric acid) is what gives Limburger cheese its aroma. These essential oils are easily made in the laboratory, but cannot be extracted from the fruit for separate use.

If the carbon chain contains one or more double linkages we get the "flowery" perfumes. For instance, here is the symbol of geraniol, the chief ingredient of otto of roses:

(CH_{3})_{2}C = CHCH_{2}CH_{2}C(CH_{3})_{2} = CHCH_{2}OH

The rose would smell as sweet under another name, but it may be questioned whether it would stand being called by the name of dimethyl-2-6-octadiene-2-6-ol-8. Geraniol by oxidation goes into the aldehyde, citral, which occurs in lemons, oranges and verbena flowers. Another compound of this group, linalool, is found in lavender, bergamot and many flowers.

Geraniol, as you would see if you drew up its structural formula in the way I described in the last chapter, contains a chain of six carbon atoms, that is, the same number as make a benzene ring. Now if we shake up geraniol and other compounds of this group (the diolefines) with diluted sulfuric acid the carbon chain hooks up to form a benzene ring, but with the other carbon atoms stretched across it; rather too complicated to depict here. These "bridged rings" of the formula C{5}H{8}, or some multiple of that, constitute the important group of the terpenes which occur in turpentine and such wild and woodsy things as sage, lavender, caraway, pine needles and eucalyptus. Going further in this direction we are led into the realm of the heavy oriental odors, patchouli, sandalwood, cedar, cubebs, ginger and camphor. Camphor can now be made directly from turpentine so we may be independent of Formosa and Borneo.

When we have a six carbon ring without double linkings (cyclo-aliphatic) or with one or two such, we get soft and delicate perfumes like the violet (ionone and irone). But when these pass into the benzene ring with its three double linkages the odor becomes more powerful and so characteristic that the name "aromatic compound" has been extended to the entire class of benzene derivatives, although many of them are odorless. The essential oils of jasmine, orange blossoms, musk, heliotrope, tuberose, ylang ylang, etc., consist mostly of this class and can be made from the common source of aromatic compounds, coal tar.

The synthetic flavors and perfumes are made in the same way as the dyes by starting with some coal-tar product or other crude material and building up the molecule to the desired complexity. For instance, let us start with phenol, the ill-smelling and poisonous carbolic acid of disagreeable associations and evil fame. Treat this to soda-water and it is transformed into salicylic acid, a white odorless powder, used as a preservative and as a rheumatism remedy. Add to this methyl alcohol which is obtained by the destructive distillation of wood and is much more poisonous than ordinary ethyl alcohol. The alcohol and the acid heated together will unite with the aid of a little sulfuric acid and we get what the chemist calls methyl salicylate and other people call oil of wintergreen, the same as is found in wintergreen berries and birch bark. We have inherited a taste for this from our pioneer ancestors and we use it extensively to flavor our soft drinks, gum, tooth paste and candy, but the Europeans have not yet found out how nice it is.

But, starting with phenol again, let us heat it with caustic alkali and chloroform. This gives us two new compounds of the same composition, but differing a little in the order of the atoms. If you refer back to the diagram of the benzene ring which I gave in the last chapter, you will see that there are six hydrogen atoms attached to it. Now any or all these hydrogen atoms may be replaced by other elements or groups and what the product is depends not only on what the new elements are, but where they are put. It is like spelling words. The three letters t, r and a mean very different things according to whether they are put together as art, tar or rat. Or, to take a more apposite illustration, every hostess knows that the success of her dinner depends upon how she seats her guests around the table. So in the case of aromatic compounds, a little difference in the seating arrangement around the benzene ring changes the character. The two derivatives of phenol, which we are now considering, have two substituting groups. One is—O-H (called the hydroxyl group). The other is—CHO (called the aldehyde group). If these are opposite (called the para position) we have an odorless white solid. If they are side by side (called the ortho position) we have an oil with the odor of meadowsweet. Treating the odorless solid with methyl alcohol we get audepine (or anisic aldehyde) which is the perfume of hawthorn blossoms. But treating the other of the twin products, the fragrant oil, with dry acetic acid ("Perkin's reaction") we get cumarin, which is the perfume part of the tonka or tonquin beans that our forefathers used to carry in their snuff boxes. One ounce of cumarin is equal to four pounds of tonka beans. It smells sufficiently like vanilla to be used as a substitute for it in cheap extracts. In perfumery it is known as "new mown hay."

You may remember what I said on a former page about the career of William Henry Perkin, the boy who loved chemistry better than eating, and how he discovered the coal-tar dyes. Well, it is also to his ingenious mind that we owe the starting of the coal-tar perfume business which has had almost as important a development. Perkin made cumarin in 1868, but this, like the dye industry, escaped from English hands and flew over the North Sea. Before the war Germany was exporting $1,500,000 worth of synthetic perfumes a year. Part of these went to France, where they were mixed and put up in fancy bottles with French names and sold to Americans at fancy prices.

The real vanilla flavor, vanillin, was made by Tiemann in 1874. At first it sold for nearly $800 a pound, but now it may be had for $10. How extensively it is now used in chocolate, ice cream, soda water, cakes and the like we all know. It should be noted that cumarin and vanillin, however they may be made, are not imitations, but identical with the chief constituent of the tonka and vanilla beans and, of course, are equally wholesome or harmless. But the nice palate can distinguish a richer flavor in the natural extracts, for they contain small quantities of other savory ingredients.

A true perfume consists of a large number of odoriferous chemical compounds mixed in such proportions as to produce a single harmonious effect upon the sense of smell in a fine brand of perfume may be compounded a dozen or twenty different ingredients and these, if they are natural essences, are complex mixtures of a dozen or so distinct substances. Perfumery is one of the fine arts. The perfumer, like the orchestra leader, must know how to combine and cooerdinate his instruments to produce a desired sensation. A Wagnerian opera requires 103 musicians. A Strauss opera requires 112. Now if the concert manager wants to economize he will insist upon cutting down on the most expensive musicians and dropping out some of the others, say, the supernumerary violinists and the man who blows a single blast or tinkles a triangle once in the course of the evening. Only the trained ear will detect the difference and the manager can make more money.

Suppose our mercenary impresario were unable to get into the concert hall of his famous rival. He would then listen outside the window and analyze the sound in this fashion: "Fifty per cent. of the sound is made by the tuba, 20 per cent. by the bass drum, 15 per cent. by the 'cello and 10 per cent. by the clarinet. There are some other instruments, but they are not loud and I guess if we can leave them out nobody will know the difference." So he makes up his orchestra out of these four alone and many people do not know the difference.

The cheap perfumer goes about it in the same way. He analyzes, for instance, the otto or oil of roses which cost during the war $400 a pound—if you could get it at any price—and he finds that the chief ingredient is geraniol, costing only $5, and next is citronelol, costing $20; then comes nerol and others. So he makes up a cheap brand of perfumery out of three or four such compounds. But the genuine oil of roses, like other natural essences, contains a dozen or more constituents and to leave many of them out is like reducing an orchestra to a few loud-sounding instruments or a painting to a three-color print. A few years ago an attempt was made to make music electrically by producing separately each kind of sound vibration contained in the instruments imitated. Theoretically that seems easy, but practically the tone was not satisfactory because the tones and overtones of a full orchestra or even of a single violin are too numerous and complex to be reproduced individually. So the synthetic perfumes have not driven out the natural perfumes, but, on the contrary, have aided and stimulated the growth of flowers for essences. The otto or attar of roses, favorite of the Persian monarchs and romances, has in recent years come chiefly from Bulgaria. But wars are not made with rosewater and the Bulgars for the last five years have been engaged in other business than cultivating their own gardens. The alembic or still was invented by the Arabian alchemists for the purpose of obtaining the essential oil or attar of roses. But distillation, even with the aid of steam, is not altogether satisfactory. For instance, the distilled rose oil contains anywhere from 10 to 74 per cent. of a paraffin wax (stearopten) that is odorless and, on the other hand, phenyl-ethyl alcohol, which is an important constituent of the scent of roses, is broken up in the process of distillation. So the perfumer can improve on the natural or rather the distilled oil by leaving out part of the paraffin and adding the missing alcohol. Even the imported article taken direct from the still is not always genuine, for the wily Bulgar sometimes "increases the yield" by sprinkling his roses in the vat with synthetic geraniol just as the wily Italian pours a barrel of American cottonseed oil over his olives in the press.

Another method of extracting the scent of flowers is by enfleurage, which takes advantage of the tendency of fats to absorb odors. You know how butter set beside fish in the ice box will get a fishy flavor. In enfleurage moist air is carried up a tower passing alternately over trays of fresh flowers, say violets, and over glass plates covered with a thin layer of lard. The perfumed lard may then be used as a pomade or the perfume may be extracted by alcohol.

But many sweet flowers do not readily yield an essential oil, so in such oases we have to rely altogether upon more or less successful substitutes. For instance, the perfumes sold under the names of "heliotrope," "lily of the valley," "lilac," "cyclamen," "honeysuckle," "sweet pea," "arbutus," "mayflower" and "magnolia" are not produced from these flowers but are simply imitations made from other essences, synthetic or natural. Among the "thousand flowers" that contribute to the "Eau de Mille Fleurs" are the civet cat, the musk deer and the sperm whale. Some of the published formulas for "Jockey Club" call for civet or ambergris and those of "Lavender Water" for musk and civet. The less said about the origin of these three animal perfumes the better. Fortunately they are becoming too expensive to use and are being displaced by synthetic products more agreeable to a refined imagination. The musk deer may now be saved from extinction since we can make tri-nitro-butyl-xylene from coal tar. This synthetic musk passes muster to human nostrils, but a cat will turn up her nose at it. The synthetic musk is not only much cheaper than the natural, but a dozen times as strong, or let us say, goes a dozen times as far, for nobody wants it any stronger.

Such powerful scents as these are only pleasant when highly diluted, yet they are, as we have seen, essential ingredients of the finest perfumes. For instance, the natural oil of jasmine and other flowers contain traces of indols and skatols which have most disgusting odors. Though our olfactory organs cannot detect their presence yet we perceive their absence so they have to be put into the artificial perfume. Just so a brief but violent discord in a piece of music or a glaring color contrast in a painting may be necessary to the harmony of the whole.

It is absurd to object to "artificial" perfumes, for practically all perfumes now sold are artificial in the sense of being compounded by the art of the perfumer and whether the materials he uses are derived from the flowers of yesteryear or of Carboniferous Era is nobody's business but his. And he does not tell. The materials can be purchased in the open market. Various recipes can be found in the books. But every famous perfumer guards well the secret of his formulas and hands it as a legacy to his posterity. The ancient Roman family of Frangipani has been made immortal by one such hereditary recipe. The Farina family still claims to have the exclusive knowledge of how to make Eau de Cologne. This famous perfume was first compounded by an Italian, Giovanni Maria Farina, who came to Cologne in 1709. It soon became fashionable and was for a time the only scent allowed at some of the German courts. The various published recipes contain from six to a dozen ingredients, chiefly the oils of neroli, rosemary, bergamot, lemon and lavender dissolved in very pure alcohol and allowed to age like wine. The invention, in 1895, of artificial neroli (orange flowers) has improved the product.

French perfumery, like the German, had its origin in Italy, when Catherine de' Medici came to Paris as the bride of Henri II. She brought with her, among other artists, her perfumer, Sieur Toubarelli, who established himself in the flowery land of Grasse. Here for four hundred years the industry has remained rooted and the family formulas have been handed down from generation to generation. In the city of Grasse there were at the outbreak of the war fifty establishments making perfumes. The French perfumer does not confine himself to a single sense. He appeals as well to sight and sound and association. He adds to the attractiveness of his creation by a quaintly shaped bottle, an artistic box and an enticing name such as "Dans les Nues," "Le Coeur de Jeannette," "Nuit de Chine," "Un Air Embaume," "Le Vertige," "Bon Vieux Temps," "L'Heure Bleue," "Nuit d'Amour," "Quelques Fleurs," "Djer-Kiss."

The requirements of a successful scent are very strict. A perfume must be lasting, but not strong. All its ingredients must continue to evaporate in the same proportion, otherwise it will change odor and deteriorate. Scents kill one another as colors do. The minutest trace of some impurity or foreign odor may spoil the whole effect. To mix the ingredients in a vessel of any metal but aluminum or even to filter through a tin funnel is likely to impair the perfume. The odoriferous compounds are very sensitive and unstable bodies, otherwise they would have no effect upon the olfactory organ. The combination that would be suitable for a toilet water would not be good for a talcum powder and might spoil in a soap. Perfumery is used even in the "scentless" powders and soaps. In fact it is now used more extensively, if less intensively, than ever before in the history of the world. During the Unwashed Ages, commonly called the Dark Ages, between the destruction of the Roman baths and the construction of the modern bathroom, the art of the perfumer, like all the fine arts, suffered an eclipse. "The odor of sanctity" was in highest esteem and what that odor was may be imagined from reading the lives of the saints. But in the course of centuries the refinements of life began to seep back into Europe from the East by means of the Arabs and Crusaders, and chemistry, then chiefly the art of cosmetics, began to revive. When science, the greatest democratizing agent on earth, got into action it elevated the poor to the ranks of kings and priests in the delights of the palate and the nose. We should not despise these delights, for the pleasure they confer is greater, in amount at least, than that of the so-called higher senses. We eat three times a day; some of us drink oftener; few of us visit the concert hall or the art gallery as often as we do the dining room. Then, too, these primitive senses have a stronger influence upon our emotional nature than those acquired later in the course of evolution. As Kipling puts it:

Smells are surer than sounds or sights To make your heart-strings crack.



VI

CELLULOSE

Organic compounds, on which our life and living depend, consist chiefly of four elements: carbon, hydrogen, oxygen and nitrogen. These compounds are sometimes hard to analyze, but when once the chemist has ascertained their constitution he can usually make them out of their elements—if he wants to. He will not want to do it as a business unless it pays and it will not pay unless the manufacturing process is cheaper than the natural process. This depends primarily upon the cost of the crude materials. What, then, is the market price of these four elements? Oxygen and nitrogen are free as air, and as we have seen in the second chapter, their direct combination by the electric spark is possible. Hydrogen is free in the form of water but expensive to extricate by means of the electric current. But we need more carbon than anything else and where shall we get that? Bits of crystallized carbon can be picked up in South Africa and elsewhere, but those who can afford to buy them prefer to wear them rather than use them in making synthetic food. Graphite is rare and hard to melt. We must then have recourse to the compounds of carbon. The simplest of these, carbon dioxide, exists in the air but only four parts in ten thousand by volume. To extract the carbon and get it into combination with the other elements would be a difficult and expensive process. Here, then, we must call in cheap labor, the cheapest of all laborers, the plants. Pine trees on the highlands and cotton plants on the lowlands keep their green traps set all the day long and with the captured carbon dioxide build up cellulose. If, then, man wants free carbon he can best get it by charring wood in a kiln or digging up that which has been charred in nature's kiln during the Carboniferous Era. But there is no reason why he should want to go back to elemental carbon when he can have it already combined with hydrogen in the remains of modern or fossil vegetation. The synthetic products on which modern chemistry prides itself, such as vanillin, camphor and rubber, are not built up out of their elements, C, H and O, although they might be as a laboratory stunt. Instead of that the raw material of the organic chemist is chiefly cellulose, or the products of its recent or remote destructive distillation, tar and oil.